The American journey of Pope John Paul II reaches Washington today for a climactic 33 hours during which the traveling pope will make a historic visit to the White House and venture into the streets, churches and parks of a city quite different from any he has seen in this country.

Here in the nation's capital, the pope will find one president, hundreds of politicians, thousands of church leaders and perhaps more than one million of the faithful and curious reaching out for his gracious attention.

While embracing this city, however, he will also encounter a community where many have made almost a religion of politics and lead lives at odds with the strict moral preachings he has carried across America this past week.

Unlike the other large cities he has visited -- Boston, New York, Philadelphia and Chicago -- Washington is not a stronghold of Catholicism. And it is a largely white-collar community with little of the old-world, ethnic flavor that parts of those other cities still possess.

Still, Washington stands poised to welcome John Paul joyously with a red carpet richer than that usually afforded presidents and kings. For several weeks, the city has been building, painting, talking, praying, cleaning -- all in preparation for his visit.

All week, the people of Washington have seen him on television and read about him in the newspapers. Now, starting at 11 this morning when he steps off a helicopter near the reflecting pool on the Mall, they will have a chance to see this unusual man in the flesh.

Yesterday, the pilgrimage to see him had already begun. The city's hotels were filling up. A few chartered buses were rolling into town, some from Baltimore, filled with the ethnic faithful of that heavily Catholic city that so much wanted the pope to come there instead of Washington. Vigils began here and there about town last night. The people of Washington waited -- many with excitement, other with indifference:

Chip Finley of Chillum, a self-described "christmas Christian" who attends mass once a year, is going to the Mall tomorrow. Finley, 22, turned his back on the church when his father died unexpectedly at 47 four years ago and the priest young Finley revered as a boy fell in love and got married. "I hope that he [the pope] can show me a way back to the church," Finley said.

Xavier Fleurival, 51, a stocky auto mechanic from Haiti, has been praying daily at the Church of the Sacred Heart at 16th and Park Road NW in anticipation of the pope's arrival. He and his wife plan to drive as close to the mall as they can tommorrow. "When we can't drive any further, we will get out and walk." Fleurival said. "Nothing will keep us away from the Holy Father."

"POPE! POPE! WE WANT THE POPE! chanted 15 effusive members of Catholic University's women's cross-country team as they jogged in step past workmen hammering the final nails into the three-tiered stage on the Mall where the pope will appear tomorrow afternoon.

"We're pope groupies," beamed runner Cathy Vandervier, 19, who plans to spend tonight camped out on the Mall with members of the team in hopes that she can get close enough to the stage to catch a glimpse of the pope tomorrow.

Alice Williams of Northeast Washington, a Catholic all 71 years of her life, has never seen a pope in the flesh. Tomorrow she will be an usher when John Paul conducts a prayer service at the Shrine of the Immaculate Conception. She is delighted, Williams said, even though she thinks the church's opposition to abortion and birth control is out of step with the times. "Eight and nine children are impossible to feed and take care of in this age," Williams said.

Rudy Foster, a 40-year-old ice cream factory worker from District Heights, plans to watch the pro football game tomorrow afternoon. The pope may be a religious man, Porter said the other day as he waited for his children at Our Lady of Perpetual Help School in Anacostia. But the pope is also white.

"You think every white man out here is sincere about black folks? How many can you count?" Porter asked. "If he was so sincere, he'd come out to see some black churches, mix it all around. But where's he going? Where the upper class is."

Washington has a larger proportion of blacks -- some 35,000 strong -- than any other archdiocese in the nation. It is the hope of leaders of the black Catholics that the pope will say something during his time here about what they see as the church's need to address the problems of housing displacement, education and unemployment.

"If he can just let us know that he is aware of the problem, let them know that he cares and the church cares and the church ought to be about a social ministry," said the Rev. William L. Norvel of St. Benedict of the Moor Church in Northeast. "Otherwise, the effectiveness of his being here will not be long-lived in the black community."

In New York, several blacks here noted, the pope made a special effort to see the city's downtrodden, traveling out to see the people of Harlem and the South Bronx. Buton the pope's busy two-day schedule for Washington, a predominantly black city, there is no event specifically for blacks.

It was also in New York that the 59-year-old pope, with the manners of a jovial grandfather, won over the younger generation with a joyous celebration at Madison Square Garden at which he received blue jeans and a guitar before listening to some soft rock music. Although there will be nothing comparable here, John Paul's special relationship with youth has already touched them in this city.

"Usually, the popes just go on their way and talk words we can't understand. But he's an ordinary man. He can talk to youngsters," said Mark Miller, 16, a student at DeMatha High School in Hyattsville.

At Catholic University, the students have hung a banner proclaiming, "THINGS GO BETTER WITH POPE!" Hundreds of the students there plan to camp out in an all-night vigil outside the Shrine of the Immaculate Conception. And tonight, dozens of pope parties are planned, beer and all.

As John Hargendrader, 20, put it: "It's possible to be a believing Catholic and thoroughly enjoy life."

Pope John Paul II no doubt would agree with that, but he has come down hard against drugs, sex and the lifestyle espoused by many students. Still, students at Catholic University and elsewhere are among his biggest fans. "No one will run out and go to church and change their morals after this," said CU sophomore Jeni Smith. "But he'll make a lot think about their values, which is the first step to change."

As with the students, the priests and nuns of Washington seemed to accept the pope's strict words for them, saying they were not at all surprised that he reaffirmed his belief that women should not be priests and that priests should not be husbands. "Celibacy is very practical," said the Rev. Ramon A. diNardo fo Epiphany Church in Northwest. "You don't have any family to worry about . . . What's the use of being a priest if you're going to be like everyone else?"

The nation's capital is the final stop on John Paul's historic but hectic 6-city tour. He is scheduled to arrive at Andrews Air Force Base this morning and fly into the city by helicopter. He will celebrate mass at St. Matthew's Cathedral, meet with President Carter and attend receptions at the Pan American Union for the Organization of American States and the residence of the apostolic delegate before retiring for the night.

The pope will conduct a prayer service and address nuns tomorrow morning at the Shrine of the Immaculate Conception, and meet with Catholic educators and offer his blessings to students at Catholic University before conducting an ecumenical prayer meeting and offering special blessings to a group of handicapped persons at Trinity College.

Up to one million people are expected to attend the mass on the Mall which begins at 3 p.m. The pope is scheduled to leave the city by helicopter at 6:45 p.m., departing Andrews Air Force Base 45 minutes later bound for Rome.